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[SystemZ][z/OS] Refactor AutoConvert.h to remove large MVS guard #143174

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Merged
merged 3 commits into from
Jun 11, 2025
Merged

[SystemZ][z/OS] Refactor AutoConvert.h to remove large MVS guard #143174

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65c363f
use inline functions
abhina-sree Jun 9, 2025
51fdbd3
remove redundant functions
abhina-sree Jun 11, 2025
47357b1
use static var to only enableConversion once for stdout/stderr
abhina-sree Jun 11, 2025
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46 changes: 44 additions & 2 deletions llvm/include/llvm/Support/AutoConvert.h
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@

#ifdef __MVS__
#include <_Ccsid.h>
#endif
#ifdef __cplusplus
#include "llvm/Support/ErrorOr.h"
#include <system_error>
Expand All @@ -28,16 +29,58 @@
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

int enablezOSAutoConversion(int FD);
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How are these C variations of the functions handled? Do we declare macros for enableAutoConversion() if not c++ and expand that to enablezOSAutoConversion() for MVS? And how does this integrate with the c++ inline functions? It might be the inline functions for c++ call these extern "C" functions for z/OS instead of having the z/OS function in the llvm namespace that returns std::error_code.

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@abhina-sree abhina-sree Jun 10, 2025 •
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I left those guarded for now, I checked the usages and the headers were not removed from those files since being added so it's not as urgent to refactor those. The C++ functions are calling the C functions under the covers.

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Can you simplify the functions some so that the general inline functions for C++ that return std::error_code call the z/OS functions for C that return an int. I was thinking:

std::error_code llvm::enableAutoConversion(int FD) {
#ifdef __MVS__
  if (::enablezOSAutoConversion(FD) == -1)
    return errnoAsErrorCode();
#endif

  return std::error_code();
}

This would eliminate the extra z/OS functions.

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Thanks, this is done in the latest commit

int disablezOSAutoConversion(int FD);
int restorezOSStdHandleAutoConversion(int FD);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#ifdef __cplusplus
namespace llvm {

inline std::error_code disableAutoConversion(int FD) {
#ifdef __MVS__
if (::disablezOSAutoConversion(FD) == -1)
return errnoAsErrorCode();
#endif
return std::error_code();
}

inline std::error_code enableAutoConversion(int FD) {
#ifdef __MVS__
if (::enablezOSAutoConversion(FD) == -1)
return errnoAsErrorCode();
#endif
return std::error_code();
}

inline std::error_code restoreStdHandleAutoConversion(int FD) {
#ifdef __MVS__
if (::restorezOSStdHandleAutoConversion(FD) == -1)
return errnoAsErrorCode();
#endif
return std::error_code();
}

inline std::error_code setFileTag(int FD, int CCSID, bool Text) {
#ifdef __MVS__
return setzOSFileTag(FD, CCSID, Text);
#endif
return std::error_code();
}

inline ErrorOr<bool> needConversion(const char *FileName, const int FD = -1) {
#ifdef __MVS__
return needzOSConversion(FileName, FD);
#endif
return false;
}

#ifdef __MVS__

/** \brief Disable the z/OS enhanced ASCII auto-conversion for the file
* descriptor.
*/
Expand All @@ -63,9 +106,8 @@ ErrorOr<__ccsid_t> getzOSFileTag(const char *FileName, const int FD = -1);
*/
ErrorOr<bool> needzOSConversion(const char *FileName, const int FD = -1);

#endif /* __MVS__*/
} /* namespace llvm */
#endif /* __cplusplus */

#endif /* __MVS__ */

#endif /* LLVM_SUPPORT_AUTOCONVERT_H */
21 changes: 0 additions & 21 deletions llvm/lib/Support/AutoConvert.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -83,27 +83,6 @@ int enablezOSAutoConversion(int FD) {
return fcntl(FD, F_CONTROL_CVT, &Query);
}

std::error_code llvm::disablezOSAutoConversion(int FD) {
if (::disablezOSAutoConversion(FD) == -1)
return errnoAsErrorCode();

return std::error_code();
}

std::error_code llvm::enablezOSAutoConversion(int FD) {
if (::enablezOSAutoConversion(FD) == -1)
return errnoAsErrorCode();

return std::error_code();
}

std::error_code llvm::restorezOSStdHandleAutoConversion(int FD) {
if (::restorezOSStdHandleAutoConversion(FD) == -1)
return errnoAsErrorCode();

return std::error_code();
}

std::error_code llvm::setzOSFileTag(int FD, int CCSID, bool Text) {
assert((!Text || (CCSID != FT_UNTAGGED && CCSID != FT_BINARY)) &&
"FT_UNTAGGED and FT_BINARY are not allowed for text files");
Expand Down
30 changes: 19 additions & 11 deletions llvm/lib/Support/InitLLVM.cpp
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Expand Up @@ -18,18 +18,28 @@
#include "llvm/Support/Windows/WindowsSupport.h"
#endif

#ifdef __MVS__
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#else
#ifndef STDIN_FILENO
#define STDIN_FILENO 0
#endif
#ifndef STDOUT_FILENO
#define STDOUT_FILENO 1
#endif
#ifndef STDERR_FILENO
#define STDERR_FILENO 2
#endif
#endif

void CleanupStdHandles(void *Cookie) {
llvm::raw_ostream *Outs = &llvm::outs(), *Errs = &llvm::errs();
Outs->flush();
Errs->flush();
llvm::restorezOSStdHandleAutoConversion(STDIN_FILENO);
llvm::restorezOSStdHandleAutoConversion(STDOUT_FILENO);
llvm::restorezOSStdHandleAutoConversion(STDERR_FILENO);
llvm::restoreStdHandleAutoConversion(STDIN_FILENO);
llvm::restoreStdHandleAutoConversion(STDOUT_FILENO);
llvm::restoreStdHandleAutoConversion(STDERR_FILENO);
}
#endif

using namespace llvm;
using namespace llvm::sys;
Expand All @@ -41,10 +51,10 @@ InitLLVM::InitLLVM(int &Argc, const char **&Argv,
assert(!Initialized && "InitLLVM was already initialized!");
Initialized = true;
#endif
#ifdef __MVS__

// Bring stdin/stdout/stderr into a known state.
sys::AddSignalHandler(CleanupStdHandles, nullptr);
#endif

if (InstallPipeSignalExitHandler)
// The pipe signal handler must be installed before any other handlers are
// registered. This is because the Unix \ref RegisterHandlers function does
Expand All @@ -68,8 +78,8 @@ InitLLVM::InitLLVM(int &Argc, const char **&Argv,

// If turning on conversion for stderr fails then the error message
// may be garbled. There is no solution to this problem.
ExitOnErr(errorCodeToError(llvm::enablezOSAutoConversion(STDERR_FILENO)));
ExitOnErr(errorCodeToError(llvm::enablezOSAutoConversion(STDOUT_FILENO)));
ExitOnErr(errorCodeToError(llvm::enableAutoConversion(STDERR_FILENO)));
ExitOnErr(errorCodeToError(llvm::enableAutoConversion(STDOUT_FILENO)));
#endif

#ifdef _WIN32
Expand Down Expand Up @@ -97,8 +107,6 @@ InitLLVM::InitLLVM(int &Argc, const char **&Argv,
}

InitLLVM::~InitLLVM() {
#ifdef __MVS__
CleanupStdHandles(nullptr);
#endif
llvm_shutdown();
}
10 changes: 4 additions & 6 deletions llvm/lib/Support/MemoryBuffer.cpp
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Expand Up @@ -15,6 +15,7 @@
#include "llvm/ADT/SmallString.h"
#include "llvm/Config/config.h"
#include "llvm/Support/Alignment.h"
#include "llvm/Support/AutoConvert.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
Expand All @@ -34,9 +35,6 @@
#include <io.h>
#endif

#ifdef __MVS__
#include "llvm/Support/AutoConvert.h"
#endif
using namespace llvm;

//===----------------------------------------------------------------------===//
Expand Down Expand Up @@ -508,15 +506,15 @@ getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
}

#ifdef __MVS__
ErrorOr<bool> NeedConversion = needzOSConversion(Filename.str().c_str(), FD);
if (std::error_code EC = NeedConversion.getError())
ErrorOr<bool> NeedsConversion = needConversion(Filename.str().c_str(), FD);
if (std::error_code EC = NeedsConversion.getError())
return EC;
// File size may increase due to EBCDIC -> UTF-8 conversion, therefore we
// cannot trust the file size and we create the memory buffer by copying
// off the stream.
// Note: This only works with the assumption of reading a full file (i.e,
// Offset == 0 and MapSize == FileSize). Reading a file slice does not work.
if (Offset == 0 && MapSize == FileSize && *NeedConversion)
if (*NeedsConversion && Offset == 0 && MapSize == FileSize)
return getMemoryBufferForStream(FD, Filename);
#endif

Expand Down
19 changes: 11 additions & 8 deletions llvm/lib/Support/raw_ostream.cpp
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Expand Up @@ -894,21 +894,24 @@ void raw_fd_ostream::anchor() {}
raw_fd_ostream &llvm::outs() {
// Set buffer settings to model stdout behavior.
std::error_code EC;
#ifdef __MVS__
EC = enablezOSAutoConversion(STDOUT_FILENO);
assert(!EC);
#endif

// On z/OS we need to enable auto conversion
static std::error_code EC1 = enableAutoConversion(STDOUT_FILENO);
assert(!EC1);
(void)EC1;

static raw_fd_ostream S("-", EC, sys::fs::OF_None);
assert(!EC);
return S;
}

raw_fd_ostream &llvm::errs() {
// Set standard error to be unbuffered.
#ifdef __MVS__
std::error_code EC = enablezOSAutoConversion(STDERR_FILENO);
// On z/OS we need to enable auto conversion
static std::error_code EC = enableAutoConversion(STDERR_FILENO);
assert(!EC);
#endif
(void)EC;

// Set standard error to be unbuffered.
static raw_fd_ostream S(STDERR_FILENO, false, true);
return S;
}
Expand Down